Yesterday while updating the firmware on my PRS-505 I received a USB unable to power this device Error I waited for about 30 min and the reader still displayed the updating firmware message but otherwise was non-reactive. I then moved the usb cable to another usb slot and 10 min after that it stated that the firmware update was complete and everthing went blank. It is now completely unresponsive the power light is yellow and will not go off. I Have tried connecting it up to USB for an hour with no luck (it doesn't even show up as a device on the computer). I then left it plugged in on the power cable (non-USB) over night still nothing. I have tried Resetting with no effect. Any thoughts or Ideas?

If it's taking power, you should see a RED light, which will go off when the device is fully charged. The yellow just shows a USB connection (among other things, but not power), so I'd suggest trying to connect the USB cable to a different port on the computer to see if you can get a red light showing.

Alternatively, get hold of a PSP charger (with the round power connector) and charge using that. (Which is a better way anyway, as you can keep using the device while it charges with this method.)

Once charged try:
a) Sliding the power switch (check the LED, as it should show yellow during startup)
b) Pressing the reset on the back try (a) again. (Note: Reset on it's own won't do a statup!)